Using 'Biochar' To Cut Greenhouse Gas Emissions. ENN 20130329

http://www.enn.com/top_stories/article/45791
Researchers studied a plantation of miscanthus, a perennial grass which is harvested for fuel. They monitored how much CO₂, nitrous oxide and methane came from the plot's soil over two years. They also monitored soil emissions under controlled conditions in the lab.
The plots that had been treated with charcoal emitted 37% less greenhouse gases than neighboring plots that hadn't, while in the lab the impact was 55%. Most of this came from cutting CO₂ emissions, with methane playing no significant role and only a small nitrous oxide component.
"There's a lot of interest at the moment in the potential of bioenergy crops to sequester carbon in the soil, because unlike arable land these crops aren't ploughed every year so the carbon is not being regularly disturbed," says co-author Dr Jeanette Whitaker of CEH. "Biochar contains a lot of carbon in its own right, so adding it to the soil is already having an immediate sequestration effect, but our research suggests that it also reduces the CO₂ emitted by soil respiration, which makes the case for using it even stronger. It's about maximising the sustainability benefits of bioenergy crops."
Whitaker explains that in the long term, it is unlikely people will use wood as biochar. Instead, biochar can be made out of anything from municipal waste to chicken manure.
The paper appears in the journal Global Change Biology Bioenergy.